A typical and widely available method known in the art to transmit rotational power of, for example, engines and motors is to secure pulleys on driving and driven shafts, and run power transmission belts, such as V-ribbed belts and V-belts, over the pulleys. When such a power transmission belt is wet while driven, for example, the wet belt produces a known phenomenon called, such as, stick-slip; that is, the power transmission belt and the pulleys slip over each other and generate abnormal noise. Since, this slip noise from the power transmission belt is a cause of abnormal noise generated by a device, various countermeasures to the noise have been studied.
An example of such countermeasures is to wrap the surfaces of V-shaped ribs with a fabric so that, when the V belt and V-ribbed belt are looped over a rib-belt pulley for use, the contact portion between the V-ribbed belt and the rib-belt pulley is maintained low in friction coefficient.
Patent Document 1 (Japanese Unexamined Patent Publication No. 05-272593) discloses, for example, a V-belt and a flat belt whose entire bodies are wrapped with a cylindrical outer wrapping fabric. The document allows for the use of a knit fabric as the outer wrapping fabric of the belts.
Moreover, Patent Document 2 (Japanese Unexamined Patent Publication No. 2000-291743) discloses a power transmission belt with a reinforcing fabric bonded on its belt surface.
Patent Document 3 (Japanese Unexamined Patent Publication No. 2003-514206) discloses a belt having a knit fabric on its back surface.